Fix a bug discovered by the synthetic video.

src/tscut/cutting.py

@@ -153,6 +153,8 @@ def cut_recording(media: PreparedMedia, options: ProcessingOptions,
         except InvalidMediaError:
             raise InvalidMediaError("Impossible to retrieve timestamp of final i-frame.")
 
+        assert head_iframe_ts <= tail_iframe_ts
+
         checks.append(pos+head_iframe_ts-ts1)
 
         subparts = []
@@ -199,6 +201,8 @@ def cut_recording(media: PreparedMedia, options: ProcessingOptions,
             if h264_head_ts is not None:
                 h264_ts.append(h264_head_ts)
 
+        if head_iframe_ts < tail_iframe_ts:
+
             # Creating MKV file that corresponds to current part between I-frames
             # Internal video with all streams (video, audio and subtitles)
             internal_mkv_name = f'part-{partnum:d}-internal.mkv'

src/tscut/tools/ffmpeg.py

@@ -241,7 +241,7 @@ def extract_all_streams(ffmpeg_path:str, ffprobe_path:str, input_file:IO[bytes],
                 video_codec_params.extend([f'-c:v:{video_id:d}', codec, f'-level:v:{video_id:d}',
                                            level, '-pix_fmt', pixel_format])
                 video_codec_params.extend(interlaced_options)
-                video_codec_params.extend([f'-colorspace:v:{video_id}', color_space,
+                video_codec_params.extend([f'-colorspace:v:{video_id:d}', color_space,
                                          f'-color_primaries:v:{video_id:d}', color_primaries,
                                          f'-color_trc:v:{video_id:d}', color_transfer,
                                          f'-color_range:v:{video_id:d}', color_range])